JP2014090160A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module that has a simple structure and can reduce the number of manufacturing steps.SOLUTION: A solar cell module has a solar cell 6 comprising a wiring sheet 4 having a wiring portion 3 formed thereon, a light receiving face 6b for receiving light and a connection electrode 6a formed on a back surface 6c and is connected to the wiring portion 3 through a connecting member 9, a light permeable substrate 7 having light permeability, a back surface side sealing portion 5A having electrical insulation properties which is filled in at least a layer-shaped space between a wiring face 2b of the wiring sheet 4 and the back surface 6c on which the connection electrode 6a of the solar cell 6 is formed, and a light receiving face side sealing portion 5B having light permeability which is laminated in close contact with the back surface side sealing portion 5A and the light receiving face 6b of the solar cell 6 and in close contact with the light permeable substrate 7. The solar cell 6 is sealed by the back surface side sealing portion 5A and the light receiving face side sealing portion 5B.

Description

  The present invention relates to a solar cell module.

In recent years, solar power generation, which is a power generation system using natural energy, has been rapidly spread. In a solar battery module for photovoltaic power generation, a plurality of solar battery cells are arranged adjacent to each other, and each solar battery cell is electrically connected to take out electric power.
If such wiring for electrically connecting the solar cells is exposed to the light receiving surface, the light receiving area is reduced. For this reason, a back contact system in which a connection electrode is formed on the surface opposite to the light receiving surface of the solar battery cell, and the solar battery cell is connected via a connection member on a wiring sheet for wiring these connection electrodes. A connection structure has been proposed. As the connection member, for example, solder or silver paste is used.
Conventionally, the wiring sheet used for such a back contact type solar cell module prevents the movement of the heated connecting member so that the connecting member does not enter the adjacent wiring pattern at the time of wiring. An insulating layer is provided to insulate them.
For example, the solar cell back surface circuit sheet described in Patent Document 1 is provided with an insulating protective layer that covers the outer edge of the side surface and the upper surface of the circuit layer formed on the insulating base, and the circuit exposed from the insulating protective layer. Solar cells can be connected to the layers via connecting members.
A solder resist is used as the insulating protective layer of the solar cell back surface circuit sheet.

JP 2011-199020 A

However, the prior art as described above has the following problems.
When the insulating protective layer for the wiring is formed with a solder resist like the solar cell back surface circuit sheet described in Patent Document 1, there is a problem that the cost of parts of the solar cell module increases because the solder resist is expensive.
Since the solar cell module is manufactured by performing module lamination, in this module lamination step, for example, the solar cell module is heated at a temperature of 125 ° C. to 160 ° C. for about 15 to 30 minutes.
Since the insulating protective layer by the solder resist of patent document 1 carries out thermal crosslinking after printing a solder resist, the process of heating at the temperature of 120 to 160 degreeC for about 20 minutes to 60 minutes is needed, for example.
Therefore, in the technique described in Patent Document 1, since such an extra heating step is included, the thermal deterioration of the material (material) constituting the solar cell module proceeds, or the dimensional stability due to thermal contraction deteriorates. There is also the problem that there is a possibility.
Further, when constituting a solar cell module, in order to protect the solar cells from moisture and gas, for example, using a sealing material made of a translucent resin such as ethylene-vinyl acetate copolymer resin (EVA resin), The structure which sealed the photovoltaic cell is employ | adopted. This sealing material has flexibility, and also has a function as a protective layer that alleviates an impact caused by an external force applied to the solar cell module. For this reason, the sealing material needs to have a thickness that satisfies the mechanical properties necessary for mitigating the impact. On the other hand, since the insulating protective layer made of a solder resist is harder than the sealing material, there is almost no impact mitigating function.
Thus, since the solar cell module of a prior art needs to be equipped with the insulation protective layer and sealing material which each have a different function, there exists a problem that manufacturing cost and parts cost will be expensive. In addition, there is a problem that the thickness of the solar cell module is increased by the insulating protective layer.

  This invention is made | formed in view of such a subject, Comprising: A structure becomes simple and it aims at providing the solar cell module which can reduce a manufacturing man-hour.

  In order to solve the above problems, a solar cell module according to a first aspect of the present invention includes a wiring sheet having a wiring pattern formed on a surface thereof, a light receiving surface that receives light for power generation, and the light receiving surface. A connection electrode for wiring formed on the surface opposite to the surface, and the connection electrode is connected to the wiring pattern of the wiring sheet via a connection member having conductivity; and A light transmissive substrate disposed in a range covering the light receiving surface of the solar battery cell and the wiring sheet, and at least the surface of the wiring battery sheet from the surface on which the wiring pattern is formed. The backside sealing portion having electrical insulation filled in a layered space up to the surface on which the connection electrode is formed, and the backside sealing portion and the light receiving surface of the solar battery cell are in close contact with each other Stacked And a light-receiving surface side sealing portion having light transmittance closely attached to the light-transmitting substrate, and the wiring sheet and the light-transmitting property are formed by the back surface-side sealing portion and the light-receiving surface side sealing portion. It is set as the structure by which the said photovoltaic cell is sealed between board | substrates.

  The said solar cell module WHEREIN: The said back surface side sealing part is good also as a structure with a larger electrical resistivity than the said light-receiving surface side sealing part.

  The solar cell module may be configured such that a filler is added to the back side sealing portion.

  In the solar cell module, the filler may have an average particle size of 5 μm or more and 150 μm or less.

  The said solar cell module WHEREIN: The said back surface side sealing part is good also as a structure formed with the material containing 1 or more resin selected from olefin resin, polyvinyl butyral resin, and silicone resin.

  In the solar cell module, the back surface side sealing portion is formed of a material to which a pigment having a light absorbing property or a light reflecting property is added, so that the wiring pattern cannot be visually recognized from the light receiving surface side. It is good also as composition which has.

  According to the solar cell module of the present invention, the back side sealing portion that constitutes a part of the sealing portion covers the wiring portion and performs electrical insulation, so that the configuration is simplified and the number of manufacturing steps can be reduced. There is an effect.

It is typical sectional drawing which shows schematic structure of the solar cell module of embodiment of this invention. It is process explanatory drawing explaining the manufacturing process of the wiring sheet used for the solar cell module of embodiment of this invention. It is process explanatory drawing explaining the manufacturing process of the solar cell module of embodiment of this invention. It is process explanatory drawing explaining the manufacturing process of the solar cell module of embodiment of this invention following FIG. It is typical sectional drawing which shows schematic structure of the solar cell module of the 1st modification of embodiment of this invention.

Below, the solar cell module of embodiment of this invention is demonstrated with reference to an accompanying drawing.
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a solar cell module according to an embodiment of the present invention. In addition, since FIG. 1 is a schematic diagram, the dimension and the shape are exaggerated (the following drawings are also the same).

  As shown in FIG. 1, the solar cell module 50 of the present embodiment is a solar cell in which a plurality of connection electrodes 6 a for wiring are provided on the side of the back surface 6 c opposite to the light receiving surface 6 b that receives light for power generation. On the sealing part 5, the battery cell 6, the wiring sheet 4 for wiring the solar battery cell 6, the sealing part 5 stacked on the wiring sheet 4 and the solar battery cell 6 to seal the solar battery cell 6, The transparent substrate 7 laminated | stacked and the protective layer 1 laminated | stacked on the opposite side to the sealing part 5 with respect to the wiring sheet 4 are provided.

The solar battery cell 6 generates electric power by photoelectrically converting light incident from the light receiving surface 6b, and is a back contact type solar battery cell having a connection electrode 6a provided on the back surface 6c. Although FIG. 1 is a schematic diagram, the illustration is simplified. However, the number of connection electrodes 6a can be appropriately set to 2 or more as necessary.
Moreover, the number of the photovoltaic cells 6 is not particularly limited, and one or more appropriate numbers can be arranged. In the present embodiment, solar cells 6 (not shown) are arranged in parallel in the depth direction of the paper in FIG. 1 and are arranged in a lattice shape along two directions in plan view.
The planar view shape of the photovoltaic cell 6 is not particularly limited, and for example, a rectangular shape or an appropriate polygonal shape can be adopted.

  The wiring sheet 4 includes a sheet base 2 and a wiring portion 3 (wiring pattern).

The sheet base material 2 is a member that supports the wiring portion 3 on the wiring surface 2b that is one surface in the thickness direction.
The protective layer 1 is in close contact with and bonded to the back surface 2a which is the other surface of the sheet substrate 2.
As the material of the sheet substrate 2, a resin film having heat resistance that can withstand the heating temperature at the time of lamination, which will be described later, and electrical insulation can be employed. Examples of suitable film materials for the sheet substrate 2 include stretched polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyimide films.

The wiring part 3 is formed of a thin layer conductive member formed in an appropriate pattern for wiring the solar battery cells 6. As a fixing method with the sheet base material 2, for example, adhesion through a two-component curable adhesive can be employed.
The wiring part 3 has a width wider than the outer diameter of the connection electrode 6a at least at a portion connected to the connection electrode 6a of the solar battery cell 6.
As the conductive member used for the wiring portion 3, a metal foil such as a copper foil and an aluminum foil that is excellent in workability and low in cost is suitable.
In addition to the metal foil, it is also possible to use a conductive plastic film, a conductive paste, or the like that has conductivity by containing metal particles.
As a patterning method of the wiring part 3, a well-known patterning method can be adopted according to the type of the conductive member. For example, in the case of a metal foil, for example, punching or etching can be performed. In the case of a conductive plastic film, punching can be performed. In the case of a metal paste, patterning by printing is possible.

The connection electrode 6 a of the solar battery cell 6 and the wiring part 3 of the wiring sheet 4 are electrically connected by a connection member 9.
The material of the connecting member 9 is not particularly limited as long as it has conductivity, but for example, solder base or silver paste can be used.

The sealing unit 5 includes a back surface side sealing unit 5A and a light receiving surface side sealing unit 5B.
5 A of back surface side sealing parts are the layered space between the wiring surface 2b of the sheet | seat base material 2 in which the wiring part 3 of the wiring sheet 4 was formed at least, and the back surface 6c in which the connection electrode 6a of the photovoltaic cell 6 was formed. And made of a material having electrical insulation.
The back surface side sealing portion 5A is in close contact with the wiring portion 3, the connection electrode 6a, and the connection member 9 constituting the charging portion. For this reason, the electrical insulation of 5 A of back surface side sealing parts needs the electrical insulation of the grade which these charging parts do not short-circuit. A preferable electrical insulation property of the back surface side sealing portion 5A is equal to or higher than that of a solder resist conventionally used as an insulating protective layer in a printed circuit board or a solar cell module.
A preferable numerical range of electrical insulation of the back surface side sealing portion 5A is 10 ¹³ Ωcm or more in terms of electrical resistivity (volume specific resistance value).
Moreover, it is preferable that the material used for back surface side sealing part 5A is a material which is easy to soften at the time of a heating. For example, the storage elastic modulus E ′ is preferably about 10 ³ Pa to 10 ⁷ Pa when heated to 150 ° C.

As the material of the back surface side sealing portion 5A, it is possible to employ a resin material alone having such an electrical insulating property or a composite material obtained by adding an additive such as a pigment or a filler to the resin material.
As an example of a resin material suitable for the back side sealing portion 5A, an ethylene / vinyl acetate copolymer (EVA) (electrical resistivity: 10 ¹³ Ωcm) can be given.
Examples other than EVA include, for example, ethylene / methacrylic acid copolymer (EMAA) (electrical resistivity: 10 ¹⁷ Ωcm), ethylene / acrylic acid copolymer (EAA), ionomer (electrical resistivity; 10 ¹⁶ Ωcm), for example, olefin resins including polypropylene (electrical resistivity: 10 ¹⁶ Ωcm), polyvinyl butyral (PVB), silicone resin (electrical resistivity: 10 ¹⁴ Ωcm), and the like.
All of these resin materials are more preferred because they have a higher electrical resistivity than EVA and can provide better electrical insulation.
In addition, these resin materials are more preferable because a substance that may corrode wiring such as acetic acid is not generated and durability can be improved.
Further, for example, it can be obtained at a lower cost than a solder resist.
Here, the electrical resistivity is described with reference to numerical examples of appropriate grades among the resin materials.

When using a composite material as the back side sealing portion 5A, it is preferable to use a pigment as an additive because the back side sealing portion 5A can be colored.
Since the back surface side sealing portion 5A is filled so as to cover the wiring portion 3, if the back surface side sealing portion 5A is colored, the wiring portion 3 becomes invisible when viewed from the translucent substrate 7 side. The appearance of the solar cell module 50 is improved.
The kind and color of the pigment to be added are not particularly limited as long as the electrical resistivity necessary for the back surface side sealing portion 5A is obtained, and an appropriate kind and color can be adopted.
For example, titanium oxide and barium sulfate are suitable as the white pigment. The amount of these white pigments added is preferably 0.5% by weight or more and 20% by weight or less.
If the white pigment is less than 0.5% by weight, the wiring part 3 may not be sufficiently concealed.
If the white pigment exceeds 20% by weight, the amount of the pigment in the back-side sealing portion 5A becomes too large, resulting in a decrease in adhesion to the adherend and an increase in component costs.
For example, carbon black or the like is suitable as the black pigment. The addition amount of the black pigment can also be determined in consideration of concealability, electrical insulation, adhesiveness, etc. with respect to the wiring portion 3. Since the black pigment is excellent in concealing property compared with the white pigment, sufficient concealing property can be obtained if the addition amount is 0.1% by weight or more.
In particular, when carbon black is used as the black pigment, the amount added is preferably 0.1% by weight or more and 10% by weight or less.
If the carbon black is less than 0.1% by weight, the wiring part 3 may not be sufficiently concealed.
If the carbon black exceeds 10% by weight, the electrical resistivity of the back surface side sealing portion 5A becomes too low due to the conductivity of the carbon black, and there is a possibility that sufficient electrical insulation cannot be provided.

  In addition, when using a composite material as 5 A of back surface side sealing parts, it is also possible to add fillers other than a pigment, for example, in order to improve an intensity | strength or an electrical resistivity.

Examples of the filler added to the back surface side sealing portion 5A include fillers having electrical insulation properties such as resin fillers such as acrylic and inorganic fillers such as silica.
Such a filler functions as a spacer that maintains the electrical insulation and film thickness of the back surface side sealing portion 5A. For this reason, when sealing the photovoltaic cell 6 by lamination, the defect that the film thickness of 5 A of back surface side sealing parts becomes thin and can short-circuit can be prevented.
The size of the filler is preferably equal to or smaller than the film thickness of the back surface side sealing portion 5A and has an average particle size of 5 μm to 150 μm. The particle size distribution is measured using, for example, a laser diffraction method.

The thickness of the back side sealing portion 5A is preferably 30 μm or more and 450 μm or less. Also, in this range, a thinner thickness is more preferable because the amount of connection member 9 used is reduced.
If the thickness of the back surface side sealing portion 5A is less than 30 μm, the step between the wiring surface 2b and the wiring portion 3 is not filled, and a gap occurs or the light receiving surface side sealing portion 5B contacts the wiring portion 3. There is a risk of it.
If the thickness of the back surface side sealing portion 5A exceeds 450 μm, the amount of use of the back surface side sealing portion 5A and the connecting member 9 increases so much that the component cost increases.

The light-receiving surface-side sealing portion 5B is in close contact with and laminated on the back-surface-side sealing portion 5A and the light-receiving surface 6b of the solar battery cell 6 and is in close contact with the light-transmitting substrate 7, and has a light-transmitting material. Consists of.
As a material of the light receiving surface side sealing portion 5B, an appropriate resin material having light permeability can be adopted. In particular, all known sealing materials conventionally used for sealing solar cells can be employed.
As an example of a resin material suitable for the light receiving surface side sealing portion 5B, there is EVA that has been conventionally used as a sealing material for solar cells.
Examples of other than EVA include EMAA, EAA, ionomers such as olefin resins including polypropylene, PVB, silicone resins, and the like.

In the present embodiment, the back surface side sealing portion 5A contacts the charging portion such as the wiring portion 3 and the light receiving surface side sealing portion 5B does not contact the charging portion such as the wiring portion 3.
For this reason, even if EVA that generates acetic acid is used for the light-receiving surface side sealing portion 5B, the back-side sealing portion 5A is made of a material that does not generate acetic acid, thereby reliably preventing deterioration due to wiring corrosion. Can do. According to such a configuration, the durability of the solar cell module 50 can be improved.
Further, the light receiving surface side sealing portion 5B does not necessarily require electrical insulation like the back surface side sealing portion 5A, and therefore, a material having a lower electrical resistivity than the back surface side sealing portion 5A can be adopted. It is.
Therefore, since the light receiving surface side sealing portion 5B, which is used in a larger amount than the back surface side sealing portion 5A, can be made of an inexpensive material as compared with the back surface side sealing portion 5A, sealing is performed. The part cost of the part 5 as a whole can be reduced.

  The resin material used for the light-receiving surface side sealing portion 5B may be the same as the resin material used for the back surface-side sealing portion 5A as long as necessary light transmittance is obtained. In this case, when the wiring part 3 may be visible from the translucent substrate 7 side, a configuration in which a pigment or the like is not added to the back surface side sealing part 5A is also possible.

The thickness of the light receiving surface side sealing portion 5B is preferably 100 μm or more and 1000 μm or less.
If the thickness of the light-receiving surface side sealing portion 5B is less than 100 μm, the strength becomes insufficient. For example, when an external force is applied, the solar battery cell 6 may be broken.
If the thickness of the light-receiving surface side sealing portion 5B exceeds 1000 μm, the amount of the light-receiving surface side sealing portion 5B is excessively increased, resulting in an increase in component costs.

The translucent substrate 7 is a plate-like member made of a light transmissive material for guiding incident light from the outside to the light receiving surface 6 b of the solar battery cell 6, and covers the light receiving surface 6 b and the wiring sheet 4. It is arrange | positioned in the range and is closely_contact | adhered to the light-receiving surface side sealing part 5B.
The translucent substrate 7 is a member that forms the outer surface on the opposite side of the protective layer 1 in the solar cell module 50.
The material of the translucent substrate 7 is not particularly limited as long as it is light transmissive and has weather resistance necessary for the solar cell module 50. Suitable materials for the light-transmitting substrate 7 include glass, polycarbonate resin, acrylic resin, and the like.

The protective layer 1 constitutes the outer surface on the single-sided side with the light-transmitting substrate 7 in the thickness direction of the solar cell module 50, and for example, moisture, oxygen, or the like intrudes into the solar cell module 50. It is a sheet-like member for suppressing. The protective layer 1 is in close contact with and bonded to the back surface 2 a of the wiring sheet 4.
Suitable materials for the protective layer 1 include an appropriate resin material having excellent barrier properties against moisture and oxygen, a vapor-deposited film in which alumina, silicon oxide or the like is vapor-deposited on the surface of the resin film, a composite of an aluminum foil and an appropriate resin. A laminated film etc. can be mentioned.
Examples of the configuration of the resin material used for the protective layer 1 include adhesion to a laminated film in which fluororesin, PET resin, and fluororesin are laminated in this order, hydrolysis resistant PET resin, PET resin, and sheet base material 2. Examples thereof include a laminated film in which anchor coat layers for improving the force are laminated in this order.
The protective layer 1 may be formed separately from the wiring sheet 4 and then bonded to the back surface 2 a of the wiring sheet 4 or may be formed integrally with the wiring sheet 4.
Further, the protective layer 1 can be omitted when the wiring sheet 4 provides the necessary blocking properties.

Next, an example of a method for manufacturing the solar cell module 50 having such a configuration will be described.
2 (a) and 2 (b) are process explanatory views illustrating a manufacturing process of a wiring sheet used for the solar cell module according to the embodiment of the present invention. Drawing 3 is a process explanatory view explaining the manufacturing process of the solar cell module of the embodiment of the present invention. FIG. 4 is a process explanatory view illustrating the manufacturing process of the solar cell module according to the embodiment of the present invention subsequent to FIG. 3.

In order to manufacture the solar cell module 50, as shown in FIG. 2A, the protective layer 1, the sheet substrate 2, and the conductive sheet 30 for wiring are laminated in this order. At this time, an adhesive (not shown) is disposed between the layers. Here, the conductive sheet 30 for wiring is a sheet member made of the same material as the wiring part 3.
Next, this laminate is bonded by, for example, a dry laminating method.

Next, as shown in FIG. 2B, the wiring portion 3 is formed by patterning the wiring conductive sheet 30 in the laminated body.
As a patterning method, for example, when the conductive sheet 30 for wiring is a metal foil sheet such as a copper foil, an etching method can be employed. That is, after applying a resist on the wiring conductive sheet 30, the resist is patterned so as to correspond to the wiring pattern of the wiring portion 3, and the wiring conductive sheet 30 not covered with the resist is removed by chemical etching. Then, the wiring part 3 is formed. Thereafter, the resist on the wiring part 3 is removed.
In this way, a laminate of the protective layer 1 and the wiring sheet 4 is formed.
In addition, after forming the wiring sheet 4, such a laminated body may join the protective layer 1 to the back surface 2a of the sheet | seat base material 2, and may be formed.

Next, as shown in FIG. 3, the back-side sealing sheet 35 </ b> A is placed on the laminated body of the protective layer 1 and the wiring sheet 4 in an overlapping manner.
The back side sealing sheet 35A is a sheet member formed of the same material as the back side sealing part 5A in order to form the back side sealing part 5A. A through-hole 5a penetrating in the thickness direction is formed in the back surface side sealing sheet 35A corresponding to the arrangement position of the connection electrode 6a of the solar battery cell 6. The through-hole 5a has a shape that can accommodate the connection electrode 6a and can be overlapped without protruding from the wiring portion 3 at a position to which the connection electrode 6a is connected.
For this reason, each through hole 5 a forms a concave portion whose lower portion is closed by the wiring portion 3.

Next, the connection member 9 is disposed on the wiring portion 3 in the through hole 5a. For example, when the connecting member 9 is a solder paste or a silver paste, the connecting member 9 is disposed by applying a necessary amount in the through hole 5a.
Next, the solar battery cell 6 is mounted on the laminated body in which the back-side sealing sheet 35A is thus arranged. At this time, each photovoltaic cell 6 is arranged in a state in which each connection electrode 6a is inserted into the through hole 5a.
Next, the light receiving surface side sealing sheet 35B is placed so as to sandwich the solar battery cell 6 between the back surface side sealing sheet 35A, and the translucent substrate 7 is further placed on the light receiving surface side sealing sheet 35B. (See FIG. 4).
Here, the light receiving surface side sealing sheet 35B is a sheet member formed of the same material as the light receiving surface side sealing portion 5B in order to form the light receiving surface side sealing portion 5B.
Thus, the laminated body 50A in which the protective layer 1, the wiring sheet 4, the back surface side sealing sheet 35A, the solar battery cell 6, the light receiving surface side sealing sheet 35B, and the translucent substrate 7 are stacked in this order is formed. The

Next, using a laminator, lamination is performed by pressing the laminated body 50A in the lamination direction while heating.
The heating temperature at this time is a temperature at which the back surface side sealing sheet 35A and the light receiving surface side sealing sheet 35B are softened and deformed, and can be adhered and adhered to the surface of the adjacent member, and the connecting member 9 is a temperature at which the wiring part 3 and the connection electrode 6a can be joined.
Such a heating temperature is possible at a temperature of about 125 ° C. to 160 ° C., for example, although it depends on the material of the back surface side sealing sheet 35A, the light receiving surface side sealing sheet 35B, and the connecting member 9.
Therefore, compared to the configuration including a solder resist insulating layer that requires a heating temperature of about 120 ° C. to 160 ° C. for thermal crosslinking after printing, it is not necessary to perform heating other than at the time of lamination, so the heat load is small. That's it. For this reason, it is easy to prevent the malfunction that the raw material (material) which comprises a solar cell module progresses, or the dimensional stability by heat contraction worsens.

By such heating and pressing, each connection member 9 is pressed in the laminating direction inside the through hole 5a of the back surface side sealing sheet 35A and sandwiched between the wiring part 3 and the connection electrode 6a, and the wiring part 3 and the connection electrode 6a. For this reason, the back surface side sealing sheet 35 </ b> A serves to prevent the softened connection electrode 6 a from moving and adhering to a part other than the wiring part 3.
Further, the back surface side sealing sheet 35A and the light receiving surface side sealing sheet 35B are softened in a flowable state, and are in close contact with the surfaces of adjacent members. Thereby, 35 A of back surface side sealing sheets and the light reception surface side sealing sheet 35B are between the wiring sheet 4 and the photovoltaic cell 6, between the photovoltaic cell 6 and the translucent board | substrate 7, and each wiring part 3 of each. In between, it will be in the state filled between each connection electrode 6a, and will form the back surface side sealing part 5A and the light-receiving surface side sealing part 5B, respectively.
Thus, when heating is complete | finished, it solidifies in the state which each layer of 50 A of laminated bodies adhered, and the solar cell module 50 as shown in FIG. 1 is formed.

According to the solar cell module 50 of the present embodiment, the outer surfaces of the wiring part 3, the connection electrode 6 a, and the connection member 9 are shielded by the back surface side sealing part 5 </ b> A constituting a part of the sealing part 5. It is reliably electrically insulated from other charged parts that are spaced apart. Moreover, when the connection member 9 makes the wiring part 3 and the connection electrode 6a conductive, the connection member 9 can be kept within the range of the through hole 5a of the back surface side sealing part 5A, and the movement of the connection member 9 can be suppressed.
For this reason, for example, an insulating layer made of a solder resist is provided separately from the sealing material for sealing the solar cell module 50 to prevent electrical insulation of the wiring portion 3 and adhesion of solder to unnecessary portions. Compared to the above, a simple configuration can be obtained.
Further, since the solder resist is thermosetting, it is necessary to provide a step of curing before performing the step of sealing the solar battery cell 6 by lamination, but the back surface side sealing portion 5A of the present embodiment is thermoplastic. Since the resin is the main component, the solar battery cell 6 can be sealed by lamination together with the light-receiving surface side sealing portion 5 </ b> B, and can be molded simultaneously with the electrical connection by the connecting member 9.
As a result, the number of parts and the number of processes can be reduced, so that the cost can be reduced.
Moreover, if it is set as the structure by which the appropriate pigment was added to 5 A of back surface side sealing parts, it will become possible to conceal the wiring part 3. FIG. As a result, since the wiring part 3 is not visible when viewed from the outside on the translucent substrate 7 side, the gap between the solar cells 6 is uniformly covered with the colored back-side sealing part 5A. 50 appearance can be improved.
That is, since the pigment added to the back surface side sealing portion 5A can be freely selected, the solar cell module 50 having various appearance colors can be easily obtained. In particular, when a pigment having a color having a high reflectance such as white is used, the amount of light used for power generation by the reflected light increases, so that power generation efficiency can be improved.

  Further, the back side sealing portion 5A can be formed by the same laminating method as that used for forming a conventional sealing material, and thus thermally crosslinked as in the case of using an insulating layer of a solder resist. Therefore, the heating process for the manufacturing process becomes unnecessary, so that the heat load in the manufacturing process can be reduced and the deterioration of the material can be suppressed. For this reason, durability of the solar cell module 50 can be improved.

[First Modification]
Next, the solar cell module of the 1st modification of this embodiment is demonstrated.
FIG. 5 is a schematic cross-sectional view showing a schematic configuration of a solar cell module according to a first modification of the embodiment of the present invention.

As shown in FIG. 5, the solar cell module 60 of this modification includes a sealing material 8 between the sheet substrate 2 and the protective layer 1 of the solar cell module 50 of the above embodiment.
Hereinafter, a description will be given focusing on differences from the above embodiment.

The sealing material 8 is used to seal such a through-hole or wiring for wiring when an unillustrated wiring electrically connected to the wiring portion 3 is provided so as to penetrate the sheet base material 2, for example. It is a member.
As the material of the sealing material 8, EMAA, ionomer, silicone resin, polyethylene resin (PE), polypropylene resin (PP) and the like can be adopted, and additives such as a crosslinking agent and a silane coupling agent are used as necessary. May be added.

According to the solar cell module 60 of the present modification, the wiring portion 3 is covered and electrically insulated by the back surface side sealing portion 5A that constitutes a part of the sealing portion 5, similarly to the solar cell module 50 of the above embodiment. Therefore, the configuration is simplified and the number of manufacturing steps can be reduced.
In addition, by providing the sealing material 8, durability can be improved even when wiring is formed on both surfaces of the wiring sheet 4.

  It should be noted that all the components described in the embodiment and the first modification can be implemented by being appropriately combined or deleted within the scope of the technical idea of the present invention.

  Next, specific examples 1 to 3 of the above embodiment will be described.

[Example 1]
In this example, a protective layer 1 made of polyvinyl fluoride (PVF) resin film PV2111 (trade name; manufactured by DuPont), which is a fluororesin having a thickness of 25 μm, and Lumirror, which is a PET resin film having a thickness of 250 μm. (Registered trademark) S10 (trade name; manufactured by Toray Industries, Inc.) and a conductive sheet 30 for wiring made of an electrolytic copper foil having a thickness of 35 μm are two-component curable urethane adhesives. A511 / A5035 (trade name; manufactured by Mitsui Chemicals, Inc.) was used for bonding by a dry laminating method. At this time, the adhesive thickness was 5 g / m ² (dry).
Then, the wiring conductive sheet 30 made of electrolytic copper foil was patterned by an etching method to form the wiring portion 3, thereby forming a backsheet with wiring as shown in FIG.
The back side sealing sheet 35A is obtained by adding 2% by weight of carbon black to Nucrel (registered trademark) NC0809 (trade name; manufactured by Mitsui DuPont Polychemical Co., Ltd.), which is an EMAA resin, by extrusion lamination. Thus, a sheet member having a thickness of 200 μm was manufactured.
Then, on the wiring part 3 of the back sheet with wiring, a back side sealing sheet 35A having a thickness of 200 μm, a solar battery cell 6, a transparent grade EVA resin film EF1001 having a thickness of 400 μm (trade name; manufactured by Toppan Printing Co., Ltd.) ) And a light-transmitting substrate 7 made of glass having a thickness of 4 mm are stacked in this order to form a stacked body 50A.
At this time, the connecting member 9 made of silver paste was applied in the through hole 5a of the back side sealing sheet 35A.
Next, the laminate 50A was subjected to module lamination using a module laminator. The condition of the module lamination is that the laminated body 50A is left in a vacuum state at a temperature of 130 ° C. for 5 minutes, then the laminated body 50A is pressed in the lamination direction at a temperature of 130 ° C. for 3 minutes and then heated at a temperature of 150 ° C. for 30 minutes. The condition was set.
In a vacuum state and a pressurized state, bubbles are expelled and removed from the laminated body 50A, and the light-receiving surface side sealing sheet 35B is softened and closely adheres to the surface of the adjacent member. Sealing part 5B was formed. Furthermore, the cross-linking of the sealing material proceeded by heating at 150 ° C., and each member constituting the laminated body 50A was bonded.
Thus, the solar cell module 50 of Example 1 was manufactured.

[Example 2]
This example differs from the solar cell module 50 of Example 1 only in the material of the back surface side sealing portion 5A. The following description will focus on the differences from the first embodiment.
The back side sealing portion 5A of this example is obtained by adding 5% by weight of titanium oxide to Nucrel (registered trademark) NC0809 (trade name; manufactured by Mitsui DuPont Polychemical Co., Ltd.) which is an EMAA resin by extrusion lamination. The back side sealing sheet 35A formed into a sheet having a thickness of 200 μm by the T-die method was used.

[Example 3]
This example differs from the solar cell module 50 of Example 1 only in the material of the back surface side sealing portion 5A. The following description will focus on the differences from the first embodiment.
The back surface side sealing portion 5A of the present embodiment is made of the same material as the light receiving surface side sealing portion 5B. That is, it was formed using a back side sealing sheet 35A made of a transparent grade EVA resin film EF1001 (trade name; manufactured by Toppan Printing Co., Ltd.) having a thickness of 200 μm.

[Example 4]
This example differs from the solar cell module 50 of Example 1 only in the material of the back surface side sealing portion 5A. The following description will focus on the differences from the first embodiment.
The back surface side sealing portion 5A of this example is formed by applying a spherical acrylic filler having an average particle size of 50 μm to Nucrel (registered trademark) NC0809 (trade name; manufactured by Mitsui DuPont Polychemical Co., Ltd.) which is an EMAA resin by extrusion lamination. Only 3% by weight was added, and the back side sealing sheet 35A was formed into a sheet having a thickness of 150 μm by the T-die method.

[Evaluation]
Regarding the electrical insulation, in Examples 1 and 2, the electrical resistivity of the back surface side sealing portion 5A is 10 ¹⁷ Ωcm, which is much higher than the electrical resistivity of the solder resist, such as 10 ¹³ Ωcm. The insulation was very good. Further, the electrical conductivity of the back surface side sealing portion 5A of Example 3 is 10 ¹⁴ Ωcm, which is smaller than Examples 1 and 2 but larger than the solder resist, and thus has good electrical insulation.

About the concealing property of the wiring part 3, in Example 1, 2, since the black and white pigments were added, respectively, it was concealed by the back surface side sealing part 5A.
Further, when viewed from the translucent substrate 7, no color unevenness was observed. This is presumably because the viscosity of the back surface side sealing portion 5A at the module laminating temperature of 150 ° C. is larger than the viscosity of the light receiving surface side sealing portion 5B. That is, due to such a difference in viscosity, the back surface side sealing portion 5A and the light receiving surface side sealing portion 5B are unlikely to mix at the interface, and pigment diffusion is unlikely to occur.
In Examples 3 and 4, since the pigment is not added to the back surface side sealing portion 5A and the light receiving surface side sealing portion 5B, the wiring portion 3 can be seen from the translucent substrate 7, but the concealability of the wiring portion 3 can be seen. Can be used for non-critical applications.

The adhesiveness of the solar cell module 50 was good because the amounts of pigment and filler added in the back side sealing portion 5A were appropriate.
Further, regarding the durability of the solar cell module 50, in Examples 1 and 2, EVA resin was used for the light-receiving surface side sealing portion 5B, but EMAA resin was used for the back surface side sealing portion 5A. There is no reduction in durability due to the generation of corrosive products.
In Examples 1 and 2, since a cheap EVA resin is used for the light receiving surface side sealing portion 5B that is used in a large amount, the light receiving surface side sealing portion 5B also has a high function with a higher electrical resistivity than EMAA resin or the like. Compared to the case of using a new resin material, it can be manufactured at a low cost.
Moreover, in Example 4, by adding a filler to the back surface side sealing portion 5A, it is possible to suppress the back surface side sealing portion 5A from being partially thinned during lamination, and the back surface side sealing portion 5A can be made thinner. Therefore, it can be manufactured at low cost.

DESCRIPTION OF SYMBOLS 1 Protective layer 2 Sheet base material 2b Wiring surface 3 Wiring part (wiring pattern)
4 Wiring sheet 5 Sealing portion 5a Through hole 5A Back surface side sealing portion 5B Light receiving surface side sealing portion 6 Solar cell 6a Connection electrode 6b Light receiving surface 6c Back surface 7 Translucent substrate 8 Sealing material 9 Connection members 50, 60 Solar cell module 50A laminate

Claims (6)

A wiring sheet having a wiring pattern formed on the surface;
The wiring has a light receiving surface that receives light for power generation and a connection electrode for wiring formed on a surface opposite to the light receiving surface, and the connection electrode is connected to the wiring via a conductive connection member. Solar cells connected on the wiring pattern of the sheet;
A light transmissive substrate disposed in a range covering the light receiving surface of the solar battery cell and the wiring sheet; and
A back side sealing portion having electrical insulation filled in a layered space between at least the surface of the wiring sheet on which the wiring pattern is formed and the surface on which the connection electrode of the solar battery cell is formed;
A light-receiving surface-side sealing portion that has a light-transmitting property and is adhered to and laminated on the light-receiving surface of the solar cell and the back-surface-side sealing portion;
The solar cell module in which the solar cell is sealed between the wiring sheet and the light-transmitting substrate by the back surface side sealing portion and the light receiving surface side sealing portion. 2. The solar cell module according to claim 1, wherein the back surface side sealing portion has a higher electrical resistivity than the light receiving surface side sealing portion. The solar cell module according to claim 1, wherein a filler is added to the back side sealing portion. 4. The solar cell module according to claim 3, wherein the filler has an average particle size of 5 μm to 150 μm. The said back surface side sealing part was formed with the material containing 1 or more resin selected from olefin resin, polyvinyl butyral resin, and silicone resin, The any one of Claims 1-4 characterized by the above-mentioned. The solar cell module according to item. The back surface side sealing portion is formed of a material to which a pigment having a light absorbing property or a light reflecting property is added, so that the wiring pattern is not visible from the light receiving surface side. The solar cell module of any one of Claims 1-5.

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